✅ Quick answer: Test well water yearly for coliform bacteria, nitrate, pH, and TDS. Use a certified lab for health concerns, and collect the sample from the point that matches what you want to learn.
A test from the kitchen faucet tells you about the water someone drinks. A sample collected before a softener or filter tells you about the well itself. Those aren’t always the same question, so choose the sample location before opening the bottles.
QWL’s rule: The sample point must match the question.
📅 What to test and when
Swipe on mobile to see the complete testing schedule.
| When | What to test | Why |
|---|---|---|
| Every year | Total coliform bacteria, nitrate, pH, and TDS | The basic annual check recommended for private wells |
| After flooding or well repairs | Bacteria plus contaminants related to the event | Surface water or work on the well can introduce contamination |
| When taste, odor, or color changes | A panel chosen around the symptom and local risks | A change can point toward the well, plumbing, or treatment equipment |
| Before buying treatment | Target contaminant, concentration, pH, hardness, iron, manganese, and other system-specific parameters | Equipment must be sized for the actual water chemistry |
| After installing treatment | The contaminants the system is supposed to reduce | A treated sample verifies performance |
The CDC recommends checking private well water at least once each year for total coliform bacteria, nitrate, pH, and total dissolved solids. Ask your local health department what else should be tested in your area.
Test sooner after a flood, a well or pump repair, nearby land disturbance, a chemical spill, or a sudden change in taste, color, smell, or clarity. A new pregnancy or a child moving into the home is also a reason to review the testing schedule with the local health department.
🔬 DIY test or certified lab?
| Option | Best use | Main limitation |
|---|---|---|
| Test strips or color kits | Quick screening for pH, hardness, iron, and changes between tests | Limited range and precision; results depend on timing, lighting, and color matching |
| Handheld meters | Tracking pH, conductivity, or TDS when the meter is designed and calibrated for it | A TDS number doesn’t identify bacteria, nitrate, arsenic, lead, PFAS, or other individual contaminants |
| Mail-in lab kit | Annual testing, health concerns, treatment choices, and exact amounts | Costs more and requires careful collection and shipping |
| Local or state program | Certified testing and locally relevant panels | Availability, cost, and included analytes vary by location |
This hydrogen-sulfide strip is a good example of targeted screening. It answers one narrow question quickly, but it doesn’t replace the bacteria, nitrate, pH, TDS, metals, or other tests needed for a broader well-water check.
A home kit can screen the water or track equipment. Use a state-certified drinking-water lab when you need to judge whether the water is safe, plan costly treatment, meet a home-sale rule, or confirm a surprising DIY result.
County health departments sometimes offer free or lower-cost testing. The USGS recommends checking with the county first, then using a state-certified lab if a local program isn’t available.
Our water-test-kit guide compares mail-in labs and screening kits. Keep product selection there; this guide focuses on choosing and collecting the right sample.
🚰 Choose the correct sampling point
The faucet matters because treatment equipment and household plumbing can change the result. Decide which of these questions you need to answer:
- What is coming from the well? Collect untreated water before the softener, whole-house filter, UV system, or other treatment. A designated sample port near the pressure tank is often more useful than a hose that has been sitting outdoors.
- Is the whole-house system working? Compare a clearly labeled untreated sample with water collected after the whole-house equipment but before any under-sink filter.
- What are we drinking? Sample the kitchen cold-water tap or dedicated filtered-water faucet used for drinking.
- Is the plumbing adding lead or copper? Follow the lab’s first-draw or flushed-sample instructions. Don’t run the faucet first unless the protocol tells you to.
Don’t assume an outdoor spigot always represents untreated well water. It may be downstream of treatment, connected through old plumbing, or contaminated by a hose. Trace the plumbing or ask the installer before sampling.
🧪 What nearly 40 lab tests taught us
✓ We collect these samples ourselves — source-water, treated-water, and drinking-tap panels across QWL testing.
The collection point can change the meaning of an otherwise accurate result. A kitchen-tap sample measures the water delivered after everything upstream. It doesn’t isolate the aquifer when a sediment filter, softener, or whole-house system sits between the well and the faucet.
When we test treatment, we find the raw and treated sample points before opening the kit. We label each bottle set by location, treatment stage, and time. That keeps a good lab result from answering the wrong question.
A useful three-point treatment test:
- Untreated source: before all treatment
- Whole-house treated: after the main equipment
- Final drinking water: after an under-sink or RO system
You don’t need three panels for a routine annual check. Use them when you need to separate the source water from the performance of one or more treatment systems.
🧭 Choose contaminants from local risks
The annual core panel is a starting point. Nearby land use, local geology, plumbing, and the well’s history determine what else belongs on the order.
| Condition near the well | Ask about testing for |
|---|---|
| Septic system, livestock, flooding, or shallow well | Total coliform, E. coli, and nitrate |
| Farms, orchards, or heavy fertilizer use | Nitrate, pesticides, and herbicides relevant to the area |
| Fuel storage, dry cleaner, landfill, or industrial site | VOCs and site-specific chemicals |
| Local arsenic, uranium, radon, or PFAS concern | The contaminant identified by the state or health department |
| Orange stains, black stains, scale, or corrosion | Iron, manganese, hardness, pH, alkalinity, and corrosion-related metals |
Use our guide to common well-water problems to organize the symptoms, then confirm the suspected cause with the appropriate test. Appearance and odor help choose a panel; they don’t identify the contaminant.
📦 How to collect a lab sample
The lab’s instructions override any general guide. Tests may use different bottles, flow rates, fill lines, storage rules, and shipping times. Bacteria, lead, and VOC samples may each need a different method.
- Read the instructions first. Check the return deadline, shipping day, sample location, and whether the water must be flushed.
- Choose and label the sample point. Record whether it is untreated, whole-house treated, or final drinking water.
- Prepare the faucet exactly as directed. Some protocols require removing the aerator or disinfecting the outlet. Others require a first-draw sample.
- Use the supplied bottles. Don’t rinse them, pour out preservatives, or touch the inside of the cap or container.
- Fill each bottle as instructed. Follow any special rule for headspace, fill line, flow, or bottle order.
- Record the details. Note the date, time, faucet, treatment status, and anything unusual about the water or well.
- Pack and ship promptly. Use the cold pack and return method supplied by the lab. Don’t collect late in the week if the sample could sit over a weekend.
📊 Read the report before buying treatment
A lab report should show the amount found, the units, the reporting limit, and any comparison value. “Not detected” usually means the substance was below that lab’s reporting limit. It doesn’t prove the water contains none of it.
Check the units before comparing results. Milligrams per liter and parts per million are often similar for water, but micrograms per liter is a much smaller unit. Don’t compare two numbers until the analyte and units match.
If a health-related result is unexpected or too high, use another safe water source and contact the local health department. Confirm the result and its source before buying treatment. The EPA advises well owners to work with public-health officials when a result exceeds a health standard.
A positive bacteria result has its own response and retesting steps. See our guide to testing well water for bacteria rather than treating it like an ordinary mineral result.
❓ Common questions
Can I test my well water myself?
You can use a home kit to screen for pH, hardness, iron, and other basic signs. Use a state-certified lab for the annual safety panel, health concerns, home-sale rules, or treatment choices that depend on an exact amount.
Where can I get well water tested?
Start with your county or state health department. Some counties offer free or lower-cost tests and know which problems occur nearby. Otherwise, use a state-certified drinking-water lab or a mail-in service that sends the panel to the right certified lab.
How much does well-water testing cost?
Cost depends on the lab and the number of items tested. A local bacteria or nitrate test may be cheap or free. A broad panel for metals, PFAS, pesticides, or VOCs can cost hundreds of dollars. Choose the panel around the annual basics and local risks instead of testing for everything.
How many times a year should well water be tested?
Test the annual core panel at least once per year. Test again after flooding, repairs, contamination events, or changes in taste, odor, color, or clarity. Your health department may recommend a different schedule for local contaminants or household circumstances.
Test first, then choose treatment
The best test isn’t always the largest panel. It is the test that covers the annual basics, local risks, and the exact question you need answered—and collects the water from the correct point.
Once the results identify the contaminants and concentrations, use our well-water filtration guide to compare systems designed for that water profile.